Hair Treatment Process Providing Dispersed Colors by Light Diffraction

ABSTRACT

Hair was coated with polymer-containing fluid and then hot pressed to form a composite of hair and a polymer film imprinted with a nanopattern. Polychromatic light incident on the nanopattern is diffracted into dispersed colored light.

STATEMENT REGARDING FEDERAL RIGHTS

This invention was made with government support under Contract No.DE-AC52-06NA25396 awarded by the U.S. Department of Energy. Thegovernment has certain rights in the invention.

FIELD OF THE INVENTION

The present invention relates generally to providing hair with ananopatterned film that produces colors by diffracting incident light.

BACKGROUND OF THE INVENTION

Almost all hair coloring methods use colorants (dyes, for example) thatchange the color of the hair and produce a single color from the treatedhair. Coloring methods include methods for permanent coloring andmethods for temporary coloring.

Permanent coloring methods typically use ammonia to open up a haircuticle so that colorants may be deposited on the underlying haircortex. Peroxide is used to remove existing natural and artificialpigments.

Temporary methods also use colorants such as acidic dyes that do notsignificantly penetrate the cuticle. Temporary methods also don't useammonia. Shampooing eventually washes out temporary colorants and thehair's natural pigment is retained. Ground silica suspended in a polymerhas also been used to create a temporary iridescent effect.

Fiber coloration with little or no colorants occurs in nature. Peacockfeathers, for example, are known to have little or no pigmentation. Thestriking colors in peacock feathers are produced primarily fromdiffraction of incident light from nanometer scale branches of thepeacock feathers.

SUMMARY OF THE INVENTION

To achieve the foregoing and other objects, and in accordance with thepurposes of the present invention, as embodied and broadly describedherein, the present invention provides a hair treatment process. Theprocess involves coating hair with a polymer-containing fluid of asuitable soluble (and/or dispersible) polymer and inserting the coatedhair into a pressing device capable of both transforming the fluid intoa film and forming on a surface of the film a nanostructured patternsuitable for producing colors by light diffraction. Preferably, the hairis cleaned and dried before coating the hair with the fluid. The fluidoptionally includes a plasticizer. Optionally, the fluid includes asurfactant. The fluid-coated hair is pressed under conditions suitablefor forming the film having the nanostructured pattern. The hair andfilm are cooled and removed from the device. Exposure of the coated hairto incident polychromatic light (e.g. sunlight, theatrical light)results in dispersed colored light from light diffracted from the film.

The invention is also concerned with a hair treatment process thatprovides hair with a diffractive coating. The process includes coatinghair with a fluid including a polymer that has a glass transitiontemperature from about 55 degrees Celsius to about 90 degrees Celsius.Preferably, the hair is clean and dried before coating the hair with thesolution. Optionally, the fluid includes a plasticizer. Optionally, thefluid includes a surfactant. The fluid-coated hair is inserted into apressing device having a block with a nanostructured pattern underconditions suitable for forming a film with a nanostructured patterncomplementary to the pattern from the block. The fluid-coated hair ishot pressed under conditions suitable for forming the film with thenanostructure pattern. After cooling the hair and film, the hair andfilm are exposed to incident light, which results in dispersed coloredlight diffracted from the film.

The invention is also concerned with a heating iron for treating hair.The heating iron includes all of the elements of a conventional heatingiron with the exception of a heating block that has been configured witha nanostructured surface suitable for forming a complementarynanostructured pattern in a flexible film formed when a sample of haircoated with a fluid including a polymer with a glass transitiontemperature of from about 55 degrees Celsius to about 90 degrees Celsiusis hot pressed using the heating block.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthe specification, illustrate the embodiments of the present inventionand, together with the description, serve to explain the principles ofthe invention. In the drawings:

FIG. 1 shows a sketch of hot-pressing a sample of fluid-coated hairaccording to an embodiment of the invention.

FIG. 2 a shows a sketch of details of magnified fluid-coated hair priorto hot pressing, and FIG. 2 b shows a sketch of the hair after hotpressing to form film with a nanostructured pattern that diffractspolychromatic light, producing dispersed colors.

FIG. 3 shows a sketch of a sawtooth pattern that was formed in filmcoated hair that was shown to form dispersed colored light uponinteraction with sunlight and theatrical light.

FIGS. 4 a through 4 e show nanopatterns including a spiral, parabola,and hyperbola that were milled into blanks to make embodiment heatingblocks that were imprinted into polymer films that form dispersedcolored light from incident polychromatic light such as sunlight andtheatrical light.

DETAILED DESCRIPTION

This invention relates to a method and apparatus for treating hair. Hairtreated by the method becomes coated with a polymer film that diffractslight to produce dispersed colored light. In an embodiment, a colorspectrum results from light diffraction from a nanometer-scale patternimprinted onto a polymer film coated onto the hair. The nano-pattern isformed by coating the hair with a fluid that includes a polymer and hotpressing the fluid-coated hair under a few pounds per square inch (psi)pressure using a hot press that includes a suitably modified heatingblock capable of forming nano-patterns in the polymer film. The methodprovides a temporary coloration effect because the polymer can beshampooed out of the hair.

The nano-patterned block can be incorporated into a handheld devicesimilar to a common hair flatiron. A nano-patterned block may besuitably configured to provide a nanostructured pattern in film coatedhair to produce a rainbow of colors. A nano-patterned block can also besuitably configured to produce directionally specific images in thepolymer coated hair.

The net effect of applying the method to hair is that when the hairchanges position relative to a dominant light source, such as sunlightor theatrical lights, the hair color and any images incorporated intothe hair change as well.

Different nano-patterned blocks may be used for different multiple coloror image effects in the treated hair.

The hair treatment method forms a composite of hair andpolymer-containing film and creates a nanostructured pattern in the filmthat produces dispersed colored light. Suitable polymers useful withthis invention are soluble and/or dispersible in water or alcohol, donot damage the hair, and have a glass transition temperature (Tg) in arange such that a film can be formed when a fluid including polymer iscoated onto the hair, then hot-pressed and converted into a film with ananostructured pattern that diffracts light into dispersed coloredlight. The temperatures used for hot pressing the solution-coated hairshould be above the glass transition temperature (Tg) of the polymer. Inan embodiment, the pressing temperature is 20 to 30 degrees higher thanthe glass transition temperature of the polymer. The fluid and polymertherein should flow to conform to the nanostructured features of thenanostructured block of the hot pressing device. A suitable range for Tgof the polymer is a range from about 55 degrees Celsius to about 90degrees Celsius.

Suitable polymers with a Tg from about 55 degrees Celsius to about 90degrees Celsius include, but are not limited to, a poly-lactic acid, apolyvinyl alcohol, acrylic acids, acrylates, polyurethanes, copolymersthereof, and mixtures thereof.

The fluid may be a polymer-containing solution. The fluid may be apolymer-containing suspension. The fluid may be a polymer-containingdispersion, such as a polymer-containing emulsion. The invention hasbeen demonstrated using a fluid that is a commercially availablepolymer-containing dispersion. The polymer-containing fluid may includea plasticizer. The polymer-containing fluid may include a surfactant.The polymer-containing fluid may include an emulsifier. These additionalcomponents may be optional components of the fluid so that it issuitable for coating the hair and for the subsequent heating thattransforms the fluid into a film with a surface imprinted with ananostructured pattern capable of diffracting incident light intodispersed colors that are visible on the film-coated hair.

The film-coated hair after heat treatment may be thought of as acomposite of the hair and the polymer-containing film that diffractsincident polychromatic light into dispersed colors.

The polymer-containing fluid typically includes a liquid chosen fromwater (providing a aqueous polymer-containing solution), an alcohol(e.g. ethanol), or mixtures of water and alcohol.

No dyes are required for the heat treatment process because the colorresults from diffraction of light and not from any dye. Color can beremoved by wetting or shampooing the treated hair.

Suitable polymers are polymers that are removable from the hair bywetting or shampooing. These include, but are not limited to, polymerssuch as polyvinyl alcohol, acrylates, and polylactic acid that aresoluble and/or dispersible.

An embodiment device for treating hair includes a standard hair presswith a nano-patterned thermal block inserted into the hair press. Afterforming a composite of the hair with the polymer, the composite istreated using the hair iron by hot pressing. The result of the treatmentis a thin film composite of hair and polymer that diffracts light toproduce color.

An embodiment nano-patterned thermal block may be prepared using anyknown method and device for such as, but not limited to, focused ionbeam (FIB), photonic lithography, e-beam lithography, tool machining,ruling engines, diamond turning devices, and any other method or devicethat can produce nanometer scale features.

FIG. 1 shows a sketch of hot pressing a sample of fluid-coated hairaccording to an embodiment of the invention. The hot press 10 includespress jaws 12 and heating element 14 for heating the jaws 12. As FIG. 1shows, adjacent each of jaws 12 is a platen 16. Adjacent one of platens16 is a backing layer 18 such as a layer of a heat-resistantcommercially available polymer such as but not limited to TEFLON.Adjacent the backing layer 18 is heating block 20 configured with ananopatterned surface 22 facing fluid-coated hair sample 24. Thefluid-coated hair sample 24 is coated with the polymer-containing fluidthat may optionally include one or more of a plasticizer, a surfactant,and an emulsifier. The fluid may be a dispersion containing a polymer, aplasticizer, a surfactant, and an emulsifier. Backing layer 26 (e.g.aluminum foil) adjacent sample 24 and platen 16, which is adjacent pressjaw 12. FIG. 1 shows force being applied to jaws 12 in order to pressthe jaws 12 together, which squeezes together all elements in betweenthe jaws (i.e. platens 16, backing layer 18, heating block 20 withsurface 22, sample 24, and backing layer 26) while an electric currentis sent to heating element 14, which heats the jaws 12 and makes thepressing a hot pressing. Enough current is sent to heat the device to atemperature suitable for forming a film imprinted with the nanopatternedsurface 22 of heating block 20. As the sample of coated hair 24 ishot-pressed, a film forms with a surface imprinted with a nanopatternthat complements the nanopatterned surface 22 facing the sample. Thepressing is continued for a suitable time, pressure, and temperatureuntil the fluid that coats the hair conforms to the nanopatternedsurface 22 so that a film having this nanopatterned surface may beformed that will diffract incident polychromatic light into dispersedcolors of light. After the hot pressing, the pressing force isdiscontinued. The pressed sample is removed from the hot press andallowed to cool.

FIG. 2 a shows a “before pressing” sketch of details of magnifiedfluid-coated hair prior to hot pressing, and FIG. 2 b shows an“after-pressing” sketch of the hair after hot pressing to form film witha nanostructured pattern that diffracts light. The sketches arecross-sectional views. FIG. 2 a shows individual strands from the hairsample coated with the polymer-containing fluid. The hair shafts 1 areeach coated with the polymer-containing fluid 2. There is space inbetween individual strands of coated hair. A result of hot pressing is afilm that binds the individual hairs into a composite (FIG. 2 b). AsFIG. 2 b shows, surface portions of the polymer film are imprinted fromthe heating block surface 22 with a nanopattern 3 that diffractsincident polychromatic light into dispersed colors.

In an embodiment, a nanopatterned heating block 22 with a sawtoothpattern was prepared and used to prepare a diffractive film fromfluid-coated hair. A metal block with a sawtooth pattern was preparedusing a scribe machine to mill a sawtooth pattern into a metal blank. Asoda-lime glass casting of the patterned metal was then used as theheating block. The hair sample was human hair that had been cleaned anddried. The hair sample was hot pressed at a pressure of about 3-7 psi ata temperature above the glass transition temperature of the polymer. Theresult was a composite film including hair and polymer. Thenanostructured block imprinted a complementary sawtooth pattern into thefilm, shown in FIG. 3. This pressed sample was demonstrated to formdispersed colors of light from polychromatic sunlight and theatricallight incident upon the sawtooth-patterned surface of the film.

A variety of other nano-patterned thermal blocks were prepared using afocused ion beam (FIB). FIB pattern generator control files were writtenfor this purpose of forming nanopatterns suitable for light diffractionof incident polychromatic light.

FIGS. 4 a through 4 e shows show several nanopatterns that were preparedand were imprinted into a surface of a polymer film that was not coatedonto hair. FIG. 4 a shows a spiral pattern with a circular envelope thatwas milled to form a patterned block using the pattern generator controlfile SpiecqarcRounded2@1.str. FIG. 4 b shows a nanopattern of concentricparabolic rings made using the pattern generator control fileParabExactArc10.str. FIG. 4 c shows a nanopattern of concentrichyperbolic rings made using the pattern generator control fileHyperpbExactarc10.str. FIG. 4 d shows a moth-eye pattern of rectangularpits with different pitch in vertical and horizontal directions madeusing the pattern generator control file Smotheye2@30.str. FIG. 4 eshows a spiral with an elliptical envelope made using the patterngenerator control file ConcentricEllipsesEqArcFlat10.str. Each of thenanopatterns was milled into a metal blank to produce a nanopatternedheating block that was imprinted into a polymer film that diffractsincident polychromatic light into dispersed colors. It is believed thathair provided with these types of films with these nanopatterns willdiffract incident polychromatic light into dispersed colors.

A description of how FIB has been used for milling three-dimensionalfeatures on nanometer scale into media such as metal can be found inU.S. Pat. No. 5,773,116 and U.S. Pat. No. 5,721,687, both incorporatedby reference. U.S. Pat. No. 6,583,933, incorporated by reference, alsodescribes milling using a FIB to form aggregates of pits of low symmetrythat produce directional diffraction gratings with blaze emphasizing aparticular arbitrary spectral range.

A mastering process similar to that used for CDROM replication may beused to prepare nano-patterned heating blocks after first preparing amaster block. To prepare the master block, a mill pattern is written fora FIB milling device and applied to a master blank to convert the masterblank into a master for the heating block. The master blank may be ametal blank made from a metal such as nickel, titanium, aluminum,tungsten, silicon, and the like. The master block is used to prepare thenano-patterned heating block. Heating blocks may be made of, forexample, soda lime glass.

It is envisioned that a commercially available heating hair iron, suchas one made by CHI or BABYLISS, could be modified according to anembodiment of this invention, by replacing a heating block in thecommercially available hair iron with a heating block suitablyconfigured with a nanopattern such as the aforementioned sawtoothnanopattern or some other nanopattern such as a nanopattern shown inFIG. 4. A nano-patterned heating block prepared by FIB milling, or bysome other process for creating suitable nanopatterns, could be used tomodify the heating block of the commercially available heating device.Alternatively, a blank heating block adapted to fit into thecommercially available heating iron could be milled with a nanopatternsuitable for heating solution-coated hair and imprinting a complementarynanopattern into the resulting film. It is envisioned that acommercially available heating iron, such as one made by CHI orBABYLISS, could be modified to produce an embodiment apparatus thatcould treat fluid-coated hair according to the aforementioned processfor providing hair with a film imprinted with a nanopatterned surfacethat would diffract incident polychromatic light into dispersed colors.This way, a person could treat their own hair or another person's hairaccording to an embodiment of this invention and provide their own hairor another person's hair with a nanopattern-imprinted polymer-containingfilm that diffracts polychromatic light such as sunlight or theatricallight into dispersed colored light.

The method of the invention was demonstrated using human hair andcommercially-available polymer-containing fluids known by the commercialname KOLLICOAT MAE 100P.

These fluids are dispersions that are reported to include a 1:1copolymer of methacrylic acid and ethyl acrylate. They have beenreported to also include sodium laurate and polysorbate 80, which are asurfactant and emulsifier derived from polyethoxylated sorbitan andoleic acid. Samples of human hair were mixed with the KOLLICOAT MAE100P. In one embodiment, an 18% by weight dispersion of KOLLICOAT MAE100P in water was used to prepare a hair-polymer film composite having athickness of 13 micrometers. In another embodiment, a 4.2% by weightdispersion of KOLLOCOAT MAE 100P in ethanol with 10% triethyl citrateplasticizer was used to prepare a hair-polymer film composite having athickness of 3-4 micrometers. Each of the films after hot pressing witha nanopatterned heating block diffracted polychromatic light intodispersed colors.

It should be understood that the invention is not to be limited to usingany particular polymer-containing fluid with any particular addedcomponents of plasticizers, surfactants, emulsifiers, and the like, andthat any polymer-containing fluid suitable for forming a film on thehair after hot pressing to conforms to a suitable nanopattern in aheating block falls within the scope of this invention.

The invention is not limited to any particular nanopattern. Patterns maybe produced according to fashion whim. Suitable nanopatterns are anythat are capable of diffracting polychromatic light into dispersedcolors of light.

An embodiment of the treatment may provide color images that appearmomentarily as the hair moves on the head. Movement of the head resultsin changing the relationship between the film-coated hair and someonelooking at the hair. A person looking at the hair detects the dispersedcolors, which appear when the angle of reflection of the incident lightpermits the viewer to observe the dispersion of the colors.

The method of hair treatment is an example of a temporary method becausepolymers that are soluble and/or dispersible polymers are chosen for theprocess. Thus, the color is removed when the hair is cleaned byshampooing, which dissolves the polymer, which removes the nanopattern.

This process for hair treatment provides a means for arbitrarydirectional control of color reflected from illuminated hair, and forembedding local iridescent color regions into hair using suitablenanopatterns that diffract light into dispersed colors.

The foregoing description of the invention has been presented forpurposes of illustration and description and is not intended to beexhaustive or to limit the invention to the precise form disclosed, andobviously many modifications and variations are possible in light of theabove teaching.

The embodiments were chosen and described in order to best explain theprinciples of the invention and its practical application to therebyenable others skilled in the art to best utilize the invention invarious embodiments and with various modifications as are suited to theparticular use contemplated. It is intended that the scope of theinvention be defined by the claims appended hereto.

What is claimed is:
 1. A hair treatment process comprising: a. coatinghair with a fluid comprising a suitable polymer; b. placing the coatedhair in a pressing device, the pressing device comprising ananopatterned surface which is capable of diffracting incident lightinto dispersed colors, the pressing device capable of transforming thecoated hair into a hair-polymer film composite, the hair-polymer filmcomposite having a surface with a nanostructured surface pattern; c.pressing the coated hair with the pressing device under conditionssuitable for forming the hair-polymer film composite; and d. removingthe hair-polymer film composite from the pressing device.
 2. The hairtreatment process of claim 1, further comprising cleaning and drying thehair prior to coating the hair with the fluid.
 3. The hair treatmentprocess of claim 1, wherein the fluid is a dispersion.
 4. The hairtreatment process of claim 1, wherein the fluid has a glass transitiontemperature of from about 55 degrees Celsius to about 90 degreesCelsius.
 5. The hair treatment process of claim 1, wherein the fluidfurther comprises a plasticizer.
 6. The hair treatment process of claim1, wherein the fluid further comprises a surfactant.
 7. The hairtreatment process of claim 1, wherein the fluid is an aqueous fluid. 8.The hair treatment process of claim 1, wherein the fluid furthercomprises an alcohol.
 9. The hair treatment process of claim 8, whereinthe alcohol is ethanol.
 10. The hair treatment process of claim 1,wherein the polymer is selected from the group consisting of poly-lacticacid polymers, acrylate polymers, polyvinyl alcohol polymers,polyurethane polymers, copolymers thereof, and mixtures thereof.
 11. Thehair treatment process of claim 1, wherein the coated hair is pressedwith the pressing device at a pressure of from about 3 psi to about 7psi.
 12. The hair treatment process of claim 1, wherein the polymer hasa glass transition temperature, and the coated hair is pressed with thepressing device at a temperature above the glass transition temperatureof the polymer.
 13. The hair treatment process of claim 1, wherein theincident light is selected from the group consisting of white light,sunlight, theatrical light, and combinations thereof.
 14. The hairtreatment process of claim 1, wherein the nanopatterned surfacecomprises a pattern selected from the group consisting of sawtoothpatterns, spiral patterns, ring patterns, Archimedean patterns,ellipsoidal patterns, patterns having hyperbolic rings, patterns havingparabolic rings, and combinations thereof.
 15. The hair treatmentprocess of claim 1, wherein the hair-polymer film composite isremovable.
 16. The hair treatment process of claim 15, wherein thehair-polymer film composite is removable by shampooing.